The Liquid Crystal Display (LCD) possesses advantages of thin body, power saving and no radiation to be widely used in many application scope, such as LCD TV, mobile phone, personal digital assistant (PDA), digital camera, notebook, laptop, and dominates the flat panel display field.
The Active Matrix Liquid Crystal Display (AMLCD) is the most common liquid crystal display device at present. The Active Matrix Liquid Crystal Display comprises a plurality of pixels, and each pixel comprises a Thin Film Transistor (TFT). The gate of the TFT is coupled to the scan line extending along the horizontal direction. The drain of the TFT is coupled to the data line extending along the vertical direction. The source of the TFT is coupled to the corresponding pixel electrode. When a sufficient positive voltage is applied to some scan line in the horizontal direction, all the TFT coupled to the scan line will be activated to write the data signal loaded in the data line into the pixel electrodes and thus to show images to control the transmittances of different liquid crystals to achieve the effect of controlling colors.
The driving of the level scan line (i.e. the gate driving) in the present active liquid crystal display is initially accomplished by the external Integrated Circuit (IC). The external IC can control the charge and discharge stage by stage of the level scan lines of respective stages. The GOA technology, i.e. the Gate Driver on Array technology can utilize the array manufacture processes of the liquid crystal display panel to manufacture the driving circuit of the level scan lines on the substrate around the active area, to replace the external IC for accomplishing the driving of the level scan lines. The GOA technology can reduce the bonding procedure of the external IC and has potential to raise the productivity and lower the production cost. Meanwhile, it can make the liquid crystal display panel more suitable to the narrow frame design of display products.
The embedded touch control technology is to combine the touch control panel and the display panel as one, and to merge the function of the touch control panel into the liquid crystal panel to make the liquid crystal panel equipped with functions of display and sensing the touch control inputs at the same time. With the rapid development of the display technology, the touch control display panel has been widely applied and accepted, used by the people. For example, the smart phone, the flat panel computer and etc. all use the touch control display panel.
The present embedded touch control technology can be categorized into two types: one is that the touch control circuit is on the liquid crystal cell (On Cell), and the other is that the touch control circuit is inside the liquid crystal cell (In Cell).
As the GOA driving circuit applied in the touch display panel awakens the panel screen, it requires a certain duration for realizing the (All Gate On) function that all the output ends of the respective GOA units, and the gate scan driving signals are all outputted at the same time for activating the TFTs of all pixels in the panel, and clearing the residual voltage level in the pixel. Meanwhile, it is also required that as the GOA circuit normally works in display procedure, it has to shut down the output ends of the GOA units of all stages in the GOA circuit at arbitrary moment, and to stop the output of the gate scan driving signal for performing the touch scan. After the touch scan is accomplished, the GOA circuit returns to be normal, and continues to output the gate scan driving signal for display. However, the circuit failure risk exist as the GOA circuit applied in the touch display panel according to prior art achieves the All Gate On and the touch scan function, and the stability is worse.